1. Field of the Invention
The present invention is a control valve with a single set of orifices that are formed from a single pair of discs. The design of the present valve's internal components are easier and less expensive to make, easier to insert into and remove from the valve body, and can be used to retrofit into existing valve bodies to replace more complicated and expensive components.
2. Description of the Related Art
The prior art is represented by three of the present inventor's previously invented valves. The first previous valve by the present inventor was the Woods in-line flow-control choke valve which was marketed by Woods Energy Products, Inc. in Tulsa, Okla. This valve was a straight through valve with double sets of double discs and two orifices. The problem with this valve was that it was hard to put actuators on it.
The second previous valve by the present inventor was the valve taught in U.S. Pat. No. 5,217,046 entitled Top Entry Flow Control Valve with Two Sets of Orifices, and the third previous valve by the present inventor was the valve taught in U.S. Pat. No. 5,365,978 and was also entitled Top Entry Flow Control Valve with Two Sets of Orifices. The present invention is an improvement over the inventor's third previous valve which is shown in FIG. 1.
Referring now to FIG. 1, the third previous valve 10A has several problems. The first problem with the third previous valve 10A is that it is difficult to manufacture. Specifically, the inside of the body 12A of the valve must be machined to receive pins 154 that hold the internal components of the valve 10A within the valve body 12A. Also, the wear sleeve 218 that receives the opposite ends of the pins 154 has to be machined to receive those pins 154. Additionally, the third previous valve 10A required intricate machining of engaging flanges 166 and 200 as a means of linking the wear sleeve 218 to the rotatable cylinder 20A in order to remove both the rotatable cylinder 20A and the wear sleeve 218 from the valve body 12A in order to replace the discs 16 and 18 and the wear insert 144. Because of the degree of difficulty in manufacturing the third previous valve 10A, it is costly to make.
Still another problem with the third previous valve 10A is that it is difficult to assemble and to disassemble for servicing. In order to insert the internal components of the valve 10A into the valve body 12A, the pins 154 had to be properly aligned with the machined openings in the valve body 12A so that the pins can be pressed in. This is not an easy task. When the internal components of the valve 10A are removed from the valve body 12A, the pins 154 may or may not be also be removed with the internal components. Also, in order to insert or remove the internal components, the flanges 166 and 200 must be turned in such an orientation so that they engage each other to thereby link the internal components together as a unit.
The present invention addresses these problems by providing a control valve with a single set of orifices that are formed from a single pair of discs. The design of the present valve's internal components are easier and less expensive to make, easier to insert into and remove from the valve body, and the internal components can be used to retrofit into existing valve bodies to replace more complicated and expensive components.